Subtropical Storm One in the 1978 Atlantic hurricane season is the only Atlantic subtropical cyclone on record to form during the month of January. The formation of Subtropical Storm One marked the second-earliest start to an Atlantic hurricane season, after a hurricane in 1938 which formed on January 3. It formed on January 18 well to the east-northeast of the Lesser Antilles, and throughout its duration it maintained a general westward track. The storm attained peak winds of about 45 mph (75 km/h), and only briefly threatened the northeastern Caribbean islands before dissipating on January 23. There have been only three other tropical cyclones in January – Hurricane Alice in 1955 and Tropical Storm Zeta in 2006 – both of which formed in the end of December and lasted into January; and Hu